Most of the AT&T Center crowd had already cleared out, both teams were long overdue to hit the showers, the result was beyond doubt and the announcing crews were getting restless. The three referees convened near center court, anyway, to undertake one of the least important video reviews of the season.

The question before them: Did Elijah Millsap release a mid-range jumper before the shot clock expired in a game that the Jazz trailed the Spurs by 37 points with 18.3 seconds left in regulation? If he got the shot off, the score would read 118-83 and San Antonio would dribble out the win. If not, the score would be 118-81 and San Antonio would dribble out the win.

The officiating crew looked sheepish as they convened. The review dragged on—as they tend to do—and finally the ruling came down: no basket. “I don’t think it’s going to affect the point spread,” Spurs color commentator Sean Elliott impatiently quipped on the broadcast, as San Antonio went on to dribble out the victory as expected.

Indeed, the gamblers weren’t impacted. However, this meaningless officiating decision did humorously contribute to a noteworthy, albeit temporary, statistical achievement. Had Millsap’s basket counted, the Spurs would have won by 35 points and their point differential this season would have been +13.077. By wiping off the basket, the Spurs’ 37-point win bumped their point differential up to +13.154. Who cares?

Well, as it so happened, Millsap’s non-basket pushed San Antonio above Golden State (+13.08) for No. 1 in the NBA’s point differential rankings.

Gregg Popovich’s club has accumulated so many wins in June over the years that all mid-December factoids are trivialities by comparison. But, still, this was a stunner. The Warriors—owners of 24 straight wins and the best start in NBA history, media darlings led by the reigning MVP Stephen Curry, fan favorites who drew cult-like crowds on a recent seven-game road trip—were, at least in the technical sense, no longer the league’s most dominant team.

Golden State fans will point to the many fourth quarters that Curry and his fellow starters have rested, they will point to the absence of Harrison Barnes, and they will point to the standings in making their case for the “most dominant” tag. As they should.

The intended message here is straightforward, but it needs to be shouted more loudly than it has been: the fast-starting defending champs aren’t lapping the entire field. Every favorite needs a foil, and the Spurs look increasingly suited to that task.

Recently, the most common six-word story about a potential Warriors/Spurs matchup has been: “Best offense versus best defense. Ooooohhhhh.” That last word is a squeal, the type of noise you might make after Curry hits an off-balance 40-footer or Kawhi Leonard robs a dribbler blind and coasts to an uncontested dunk. Golden State and San Antonio staked their claims to the league’s most efficient offense and stingiest defense, respectively, early this season. Both teams remain comfortably at the top of those charts entering Wednesday’s action, with no cause to believe they’ll slip any time soon.

But that simplified story, while easily digestible and accurate, leaves out half of the intrigue. Golden State’s portion of the missing information is fairly well-known. The Warriors have the defensive personnel to make life miserable for anybody and everybody, and they won 67 games and a title last season thanks to that elite balance and versatility. With most of its rotation back, Golden State ranks fifth in defense and believes that it’s capable of even more.

The last piece of this equation is the Spurs’ offense, which hasn’t gotten much attention this season. San Antonio’s symbolic move past Golden State on the point differential charts, however, should serve as notice that there are now two teams functioning at an elite level on both sides. In fact, the Spurs now rank third in offensive efficiency after posting four wins by at least 22 points each in their last five games. For now, Golden State and San Antonio are the only two teams to rank in the top five on both offense and defense—the sign of a true blue-chip championship contender.

Conventional wisdom suggested that there would be growing pains for the Spurs, who needed to shift responsibilities to Kawhi Leonard, incorporate LaMarcus Aldridge, and gauge the potential declines of Tim Duncan, Tony Parker and Manu Ginobili. Conventional wisdom also suggested that Popovich and his staff would be able to figure things out. On both counts, that’s basically what’s happened.

The pleasant surprise—and it really shouldn’t be a surprise after so many seasons of consistent greatness—is how machine-like San Antonio’s offensive improvement has been. Here’s a simple look at San Antonio’s offensive rating so far this season, at the two-week mark, the four-week mark, the six-week mark and through Monday’s game. The improvement is so steady that it’s a bit haunting, as if it’s going to continue refining itself forever like a deadly, mutating virus.

While the Warriors’ offense has been a non-stop fireworks show this season, the Spurs’ attack has been a thunderstorm gradually gaining momentum and force. Importantly, it shows no signs of easing up. On the contrary, there’s still untapped potential here, as Aldridge finds his bearings and Danny Green pulls out of an uncharacteristically shaky shooting start.

What, exactly, has been working so well recently for the Spurs’ offense? Let’s quickly run down three reasons that San Antonio’s attack is surely inspiring fear around the league.

1. Kawhi’s maturation and skill

Even though the Spurs are playing at a fairly slow pace this season, leaning heavily on their preferred big lineup that features both Duncan and Aldridge, they lead the league in passes per game. San Antonio’s offense starts early in the clock, it sees the ball whip around through multiple actions, and it forces defenses into switching situations. This approach has kept opposing coaches awake at night for years. They can beat you from anywhere, at any time!

Making this even more terrifying is Kawhi Leonard’s continued development as a one-on-one source of offense. A maturing Leonard and Aldridge—two players who can create something out of nothing—helps San Antonio compensate for the spacing issues that come with playing big lineups.

While the Spurs would prefer not to get stuck playing hero ball late in the clock, Leonard is 35-71 (48.6%) when there’s less than seven seconds left on the shot clock. Some of his scores in these situations are, frankly, demoralizing.

Imagine how disheartening it must be for a defense to hold up through pass after pass, only to watch Leonard stop on a dime and spin into a beautiful pull-up jumper…

Watch in awe as Leonard salvages a busted play by unleashing a brutal crossover before power-waltzing through multiple defenders for a layup…

This is a defense’s reward for 20+ seconds of hard work on the possession? This is San Antonio’s fall-back plan?

To be clear, Leonard is an impact-maker and problem-solver in virtually every game situation at this point. He deserves to be in the top-five of the MVP conversation because he’s as complete as they come: his defensive abilities are well-established and he continues to flaunt a diverse scoring game that makes him a threat in transition, in the post and from beyond the arc.

Skeptics are right to expect Leonard’s sizzling perimeter numbers to regress as the season continues. That’s fine, just remember how many ways he can beat defenses and how easy he often makes it look.

2. Tony Parker’s space to operate

It’s natural to look at Aldridge’s mediocre 46.8% shooting percentage and his total lack of three-pointers this season and wonder whether offensive spacing might develop into a fatal flaw for the Spurs’ big lineup. Many critics held that position before the season started, and the Warriors have a way of uncovering that particular weakness when they shift into their small ball look.

For now, though, realize that the threat of Aldridge’s mid-range shooting—imperfect as that might be—has made life easier for the Spurs in general and Parker in particular. So far this season, San Antonio is shooting 62.5% from within five feet, good enough for third in the league after ranking No. 10 last year. The Duncan/Aldridge tandem is critical to this improvement. Duncan’s passing ability from the high post allows San Antonio to find scoring opportunities off of cuts in tiny windows; the attention paid to Aldridge when he drifts to the top of the key helps make those windows bigger and more frequent.

Parker looks healthier than he did last season and during EuroBasket over the summer, and his numbers reflect that. He ranks in the top 20 in drives this season, he’s getting all the way to the basket more often (51% of his attempts are coming in the basket area, up from 42% last year), and he’s finishing more effectively (shooting 61% in the basket area, up from 57% last year).

Check out Aldridge’s role in this.

Here, Aldridge forces his man just far enough out of the paint on the weakside so Duncan can hit Parker on a bang-bang backdoor cut for a layup.

On this one, Aldridge pulls Nikola Mirotic to the weakside and then towards the free throw line as Parker probes, and probes, and probes and eventually finds another fairly routine layup. A quick and unfettered two-man game with Duncan helps pull Pau Gasol away from the rim too.

Yes, these are still precision plays because of the spacing that comes with playing two traditional bigs. Good news: San Antonio specializes in precision, particularly when Parker is moving well and when Duncan has the ball in his sure hands.

3. LaMarcus Aldridge’s comfort

The biggest linchpnn for San Antonio’s season is obviously Aldridge, its highest-profile newcomer.

Aldridge’s per-game averages—15.8 PPG and 8.8 RPG—are pedestrian by his usual standards. Early on, he admitted he was struggling to find his way and hadn’t yet decided when he should be shooting and when he should be moving the ball.

Much of this is typical minutes-related and role-related depression. After logging huge minutes in each of the past seven seasons, the four-time All-Star is now playing under 30 minutes a night on the Popovich plan. He’s also avoiding the super-heavy usage that he dealt with in Portland in each of the last two years.

Although Aldridge’s 37.9% shooting from his bread-and-butter mid-range is down from 41.5% last season, it’s hard to muster up that much concern when watching the tape from San Antonio’s recent romps.

Duncan’s influence plays a big part. San Antonio’s big-to-big interplay is coming along, allowing Aldridge clean opportunities to use his length at the rim.

Here, Aldridge gets a clean catch on an over-the-top look from Duncan. Behind his defender deep in the paint, and with no help defenders within 10 feet, Aldridge takes care of the rest with a deft pump fake and smooth finish.

Aldridge is also getting a feel for life as a garbage man on the weak side. San Antonio’s emphasis on ball and man movement often creates situations where defenses overcommit or lose their shape, leaving the backside exposed. There are opportunities aplenty for Aldridge if he cuts, dives or spins at the right moment, when the defense is otherwise preoccupied.

Here, the Spurs swing the ball from right to left and Green attacks the defense on the left wing. Meanwhile, Aldridge slips behind the defense to the block. The threat of Leonard on the perimeter helps Aldridge get even more wide open.

Much like the last clip, Aldridge feasts on another simple look below. The Spurs set this one up with a familiar baseline loop for Parker, who receives the pass on the go and immediately attacks the heart of the Jazz’s defense. As five defenders surround Parker, packing the paint, Aldridge slides to the block and waits his turn. Sure enough, Parker finds him and he’s able to finish an uncontested layup despite fumbling the pass.

Getting quality looks in the basket area for Aldridge is key to keeping him on the court against spread lineups. Simply put, he needs to punish teams when they go small. While the Spurs don’t want to totally bog down their offense by dumping the ball to him over and over on the block, they can make use of his length, touch around the hoop, and general skill level by having him play clean-up after his teammates draw defenders.

The early returns are promising: 34% of Aldridge’s shots this year are coming in the basket area, a substantial increase over last year (23%). He’s converting at a higher rate too (62% versus 58% last year). Aldridge noted when he signed with the Spurs that he was expecting lots of “easy shots,” and this is exactly what he was talking about.

*****

Limiting this survey of San Antonio’s offense to just three factors feels somewhat criminal. Manu Ginobili has been fantastic early this season, Popovich’s bench is loaded with contributors (Patty Mills, Boris Diaw, etc.), and newcomer Jonathon Simmons has been a nice find. There are, admittedly, plenty more stories to tell here.

There’s also no rush. The slow-developing crash course between the Warriors and Spurs—which might very well end up with a dream Western Conference finals matchup—is only just beginning.